Chuck



(No Model.)

G. W. FRANCIS. GHUOK.

No. 461,469. Patented Oct. 20, 1891 Error.

GEORGE \V. FRANCIS, OF READING, PENNSYLVANIA.

CHUCK.

SPECIFICATION forming part of Letters Patent No. 461,469, dated October 20, 1891.

Application filed July 24, 1891.

.To 6655 whom, it may concern;

Be it known that I, GEORGE \V. FRANCIS, a citizen of the United States, residing at Reading, in the county of Berks, State of Pennsylvania, have invented certain Improvements in Chucks, of which the following is a specification. 7

This invention has relation to that class of chucks in which are employed gripping-jaws which rotate simultaneously each on its own axis toward and from a common center in the grasping and releasing ot' the tool or blank to be operated on; and its object is to provide a chuck of the character set forth which shall possess the maximum of strength, durability, and effectiveness in operation, and at the same time be extremely simple in construction.

To these ends the invention consists in certain peculiarities in the construction, arrangement and combination of the several parts,

substantially as hereinafter described, and particularly pointed out in the claims.

In the accompanying drawings, illustrating the invention, Figure 1 is a longitudinal section of my improved drill-chuck. Fig. 2 is a plan view of the same. Fig. 3is atransverse section on the line X X, Fig. 1. Fig. 4 is a a threaded side view of the inner shell or holder and ring. Fig. 5 is a front view of said inner shell. Fig. 6 is a side view of one of the gripping-jaws. Fig. 7 is an end View of the same. Fig. 8 is a View of the ring for holding the jaws to their seats and for preventing their dropping when nearly closed.

The same letters are used to designate the same parts in the several figures.

A designates the outer shell of my improved drill-chuck, which shell is designed to contain the working parts thereof, and is formed with a horizontal opening B in its side for the passage of a screw 0, having a worm c thereon, which worm is adapted ,to engage part 01 of a shell D for rotating the same. At a suitable point between the two ends of the opening 13 is a perforated bridge I), which, in connection with the inner walls I) of the said opening, supports the screw C and allows the latter to effectively operate. The screw 0 has a recessed head for an obvious purpose. Its worm is of the same diameter as its head and its opposite end is of reduced Serial No. 400,533. (No model.)

diameter, screw-threaded, and engaged by a nut for holding it in place. The shell D contains the gripping-jaws H, and it is formed with openings E, which are so located with respect to each other and shaped as to present at the outer or front side of said shell the appearance of a trefoil, while its opposite side is recessed to form projections F, between which operate the arms I of the grippingjaws above referred to. The main portion h of said gripping-jaws are crescent-shaped, and have concave faces h, which, when the jaws are opened to their greatest capacity, form a central cylindrical opening, as indicated in'Fig. 2. The radial jaw-arms I are located out of alignment with the centers of the concave faces h. Engaging the recessed sides of said arms I is a circular spring K.

From the above the operation of my improved drill-chuck willbe readily understood, and may be briefly described as follows: The parts being properly located with the Worm c in engagement with the threaded portion (1 of the shell D, and said worm being rotated by means of a screw-wrench (not shown) applied to the end of screw 0. Said shell is rotated in one direction, which causes the gripping-jaws to rotate in the opposite direction toward a common center until their points come into contact with and firmly grip the shank of the tool or blank to be held. When it is desired to release said tool, it is only necessary to turn the worm in the opposite direction.

The ring or spring K serves to hold the jaws to their seats and prevents them from dropping when nearly closed.

From the foregoing it will be readily seen that I have provided a strong, durable, and effective self-gripping chuck of extremely simple construction, and one which will effectively hold tools of various sizes.

If the chuck is not intended to be capable of gripping below a certain minimum size, the jaws may evidently be spread so as to close to the line of a circle of such minimum size instead of closing to the actual chuck center, as shown.

I do not wish to be understood as limiting myself to the precise construction herein shown and described; but

What I claim is 1. In a drill-chuck, the combination, with an outer rigid shell and an inner rotating shell having openings and projections, as described, of gripping-jaws received by said openings in the inner shell, adapted to be moved toward a common center by the rotation of said shell, and having arms traveling between said projections thereof, substan tially as set forth.

2. In a drill-chuck, the combination, with an outer rigid shell and an inner rotating shell having openings and projections, as described, of crescent-shaped gripping-jaws received by said openings 1n the inner shell, adapted to be moved toward acommon center by the rotation of said shell, and arms on said jaws eccentric to the axis thereof and traveling between said projections of said rotating shell, all substantially as and for the purpose specified.

3. In a drill-chuck, the combination, with an outer rigid shell and an inner rotating shell having openings and projections, as described, of gripping-jaws received by said openings in the inner shell, adapted to be moved toward a common center by the rotation of said shell, and having arms traveling between said projections thereof, and a spring engaging said arms, substantially as described, and for the purpose specified.

at. In a drill-chuck, the combination, with an outer rigid shell having an opening in its side and an inner rotating shell having a screw-threaded portion registering with said opening, of a worm engaging said screwthreaded portion of the inner shell through the opening in the outer shell, and grippingjaws received by said inner shell and adapted to be moved toward a common center by the rotation thereof, substantially as described, and for the purpose set forth.

5. In a chuck,the combination, with an outer rigid shell and an inner rotating shell, of gripping-jaws mounted concentrically in said rotating shell, and means for simultaneously rotating said jaws each on its own axis, said jaws being crescent-shaped and having concave faces adapted to form a central cylindrical space when opened to their greatest capacity, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE \V. FRANCIS.

\Vitnesses:

W. G. STEW RT, F. PIERCE HUMMEL. 

